Police say 19-year-old Alexander Song had posted on websites that he was going to "kill enough people to make it to national news." Three people alerted police to the threats, and he was arrested on campus Sunday.
Investigators say Song told them he felt stressed. He was shaking and crying when he was taken into custody.
Song was not armed at the time of his arrest, and police did not find any weapons in his dorm room or his parent's home in Fulton, Md.
Last week, police responded to a call about a person screaming loudly at a dorm. Song was interviewed at the time, but officers did not find him to be a danger.
Song now faces a misdemeanor charge of disturbing school activities.
The Associated Press contributed to this report.